Grounding mechanism



Oct. 23, 1928.

c. w. WYMAN GROUNDING MECHANISM Filed March 24, 1924 e z M H w Patented Oct. 23, 1928.

Petra-r CHARLES W. WYMAN, OF CLAREMONT, NEW HAIMPSHIRE, ASSIGN OR TO SULLIVAN MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS.

GROUNDING MECHANISM.

Application filed March. 24, 1924. Serial No. 701,598.

My invention relates to grounding mechanisms and particularly to grounding mechanisms for use 1n connection wlth mlnlng mach nery.

An object of my invention is to provide an andother objects and advantages of my im-" proved construction will hereinafter more fully appear.

In the accompanying drawings I have shown for purposes of illustration oneiorm and a modification which my invention may assume in practice.

In these drawings,

v Fig. 1 is a central vertical section through a reel provided with my improvedmechanism in its illustrative form.

Fig. 2 is an enlarged detail section.

Fig. 3 is a fragmentary elevational view of a portion of the mechanism. 1 I V Fig. 45 is a detail sectional view showing a modification.

As described in my Patent 1,407 ,120, it is important to provide means for preventing the operator of a mining machine from rece1v ing a shock arising from the contact'of the operator with the machine frame should there be a grounding of any of the power wlres of the machine. For the purpose of preventing this occurring, means is provided not only for conducting the current to the machine from the reel and from some external source to the reel, but also a ground wire is laid from the machine to the reel and also from the reel back to the mouth of the entry where a connection to the track may be made for the purpose of providing an eflectual ground, it being evident that in view of the use of wooden tracks in the room, some such provision as this is essential.

In this illustrative formI have shown my improved mechanism associated with a cable reel which is adapted to be mounted upon a mining machine truck or which may even be mounted upon atrailer truck as indicated in the patent referred to. This reel comprises a pair ofheads 1 and 2 which are connected to each other by a series of members 3 about Which an electric cable is wound and which rerea- 1 support the cable and, further, the heads of f the reel are mounted by suitable sleeves sand 3 5 upon a shaft 6 which is journaled as indicated at 7 and 8 in suitable standards'Q and 10 whlch may be supported in any suitable wav, either upon a mining machine truck or upon a special reel truck. The reel is adapted to be driven by driving pulley l1 and belt connect1on 12 associated with the head 1. Thehead 2 is of a built up, construction including the mam flange 13. and a second portion 14 which has formed, thereon aprojecting annular flange 15. This latter cooperates with a flange 16 upon a housing member 17, which isheld against rotation by the interengagementof a boss 18 with a notch 19 in the standard 8, to

form a casing having within it a chamber 20. To oneside of this chamber there is secured a suitable attachment 21- through which a cable 22, herein containing four separate wires 23, 24 and 26, enters, this cable leading to a mining machine. One of these wires 23 is secured as at 27 to'the casing so that the mining machine, on which the other end of wire23 is grounded, may be grounded through this wire to the'metallic track in the main entry. The

' connections 24', 25, 26 which are connected to the machine at their remote ends are secured as indicated to rings 28, 29' and 30 which are resiliently mounted in aninsula'ting disc 31 held lnasuitable manner (not shown) tothe stationary portion of the casing 16. The extremity'. of the cable wound upon the reel passes through a suitable connection 32 and it also includes four leads, these being respec tively numbered 33, 34, 35, 36 and the leads 33, 34 and 3 5 are connected to rings which cooperate with rings 28, 29 and 30, but" which'are numbered respectively 38, 39 and 40, these rings being similarly supported in a disc of in sulating material 4:1 secured in non-rotative relation to the reel head 2, The lead 36 is grounded to the'reel as at 43 by means of the screw shown and further there is extended a connection {i l from this point to a circular contact member 45 which is loosely held by a pair of screws mounted in openings in this member to the reel head member 14 while in other oppositely disposed openings l6, springs 47 are provided which force thecontact mem-' ber 45 over into contact with an annular shoulder 48 at the end of the member 16.

From the description given the mode of operation of this mechanism will be readily apparent. It will be evident that by the wires- The wires 33, 34, 35 within the cable which is.

wound upon the reel serve to conduct current to the reel from some suitable source and by the intercoaction of the contacts 28 and 38 29 and 39, and 30 and 40,.respectively, the circuit between the power lines inthe entry and the machine is maintained notwithstandin rotation of thereel. The connection36 whic is grounded at the end of the cable in the entry, to the track rails or in some other sultable'manneryby the connection 44 and thecooperation of the contact member 45 with the shoulder 48 provides a more perfect electrical contact notwithstanding rotation of the reel and so cuts down resistance in the ground circuit. B reason of all these connections being enclose in a'single head, the entire mechanism'is readily accessible by simply dismounte ing the reel and withdrawing the cover member 17.

In Fi 4 there is shown a difierent form which t e rin 45 can assume. Therein a spring 49 is p aced in sockets 50, 51 in the ends of the ring and servesto expand the ring into tight engagement with the inner surface of the flange 15. A filler piece 52 is secured to one end of the ring andcooperates with a notch 53 in the opposite end. The same means, is'used in this form as in the one previously described to hold the ring against the member 16. This construction has as its function themore effectual sealingofthe chamber 20 so as to prevent possible ignition of mine gases as a result of sparking or arcing in the chamber. 7

7 While I have in this application specificall 7 described one form and a modification which my invention may assume inpractice, it will I be understood that these. forms of the same are shown for purposes of illustration and that the invention may be modified and embodied in various other forms without de-. parting from its spirit or the scope of the appended claims.

What I claim as new and desire to secure .by

' Letters Patent is:

1. In a mining apparatus, a reel, a stationary member coaxial therewith, said reel and member having portions cooperating to form a housing whose opposite end walls are respectively provided by said member and by said reel and whose peripheral wall is in part provided by both said member and said reel, a plurality of pairs of cooperating contacts operative-whether said reel is stationary or rotating to maintain electrical circuits and enclosed in said housing, and means rotating with said reel and engaging said stationary cluding a plurality of sets of contacting con-' ductor rings and coaxial ground connections.

3. In a mining apparatus, a reel, a cable leading from a source of power and from a ground thereto, a cable leading to a mining machine motor and to a ground on theframe of a mining machine, and connections between said cables allat one end of said reel ineluding a plurality of sets of contactingconductor rings and coaxial groundconnections including a stationary ring and resiliently mounted rotating ring cooperating therewith.

4. In a mining apparatus, a reel, a cable leading from a source of power and from a ground thereto, a cable leading to a mining machine motor and to a ground on the frame of a mining machine, and connections between said cables all atone end of said reel including a plurality of sets of contacting conductor rings and concentric ground connections including a stationary ring and a resiliently mounted rotating ring cooperating therewith and-arranged outside said conductor rings.

5. In a mining apparatus, a reel,a stationary member coaxial therewith, said reel and member having portions cooperating to form a housing, a plurality of pairs of contactscooperating on rotation of saidreel to maintain electrical circuits housed in said chamher, and means rotating with said 'reel'and engaging said stationary member for main taining electrical connection of low resistance between them nd operating to seal the joint between said portions forming a housing.

6. In an electric cable reeling apparatus, a reel, a cable containing a plurality of conductors attached to said reel and adapted to be vwound thereon, a stationary member, said reel and member having portionscooperating to form a housing, a cable leading from said stationary member having a plurality of conductors one of which is electrically connected to said stationarymember While the others are insulatedtherefrom, a contact member earned by said reel and electrically connected to one of the conductors in the cable leadmg to the reel, yielding means providing an electrical connection between said contact member and said stationary member, and other means in said housing for electrically connecting each of the remaining conductors of one cable to a corresponding conductor in the othercable, all of said connections being closed independently of the movement of said reel.

In testimony whereof I afiix my signature- CHARLES W. WYMAN. 

